There is a need in the art to securely fix a printed circuit board when it is plugged into a connector.
Printed circuit boards ("PCB's") are widely used in a broad range of industrial, commercial and consumer products, as for example, radios, TV's VCR's watches, timers and computers. The printed circuit boards come in a wide array of sizes and shapes. In various applications, the number of circuit boards necessary for certain operations may number several dozen. Space considerations are of importance, and it is generally desirable to engineer as many circuit boards as possible in a minimum of space. In view of the fact that space is critical in the printed circuit board art, the instant invention addresses a feature of this problem.
In some product applications, the end of a printed circuit board is received within a suitable connector, and cooperating terminals or contacts provide the necessary electrical interconnection between the printed circuit board and the connector. Since the printed circuit board is plugged into the connector, it is necessary that the circuit board be securely affixed to the connector as any vibration or bumping could cause the respective contacts to separate. Any such disruption may cause a break in circuitry or a possible shorting thereof.
Various solutions have been proposed to secure the printed circuit board to the connector. For example, U.S. Pat. No. 4,008,942 to Grossi proposes a solution and method for fixing the printed circuit board to the connector which uses a spring clip and a notch-out on the printed circuit board to fix the PCB to the connector. This notching-out of the printed circuit board reduces the amount of surface space on the printed circuit board for the circuit elements or pads; hence is undesirable. Further, the device of Grossi requires equal tension on both the PCB and the connector because without equal tension, the circuit board would vibrate loose. This is a further disadvantage in the Grossi patent.
U.S. Pat. No. 4,872,853 to Webster is directed to a device for retaining a printed circuit board or card in a zero insertion force ("ZIF") edge connector. The device is a U-shaped member formed from spring wire and having legs which are bent into a concave-convex shape so that the member can be resiliently elongated. In use, the U-shaped wire member is pivotally attached and in use is forced into a notched out slot on the printed circuit card. This device of Webster's has the disadvantage of having a notch cut out on the printed circuit board which loses space for circuitry on the board; in addition, the device is complicated in construction requiring modifications on the circuit board as well as the connector to accommodate the spring latching device. Moreover, since only one spring is shown, there is the possibility that the circuit board will be held in contact in an uneven manner allowing for faulty circuit contact.
U.S. Pat. No. 4,017,138 to Evans is directed to a connector but is disadvantageous in use compared to the locking means of the invention herein described because it is complicated in construction, would be expensive to make, and would require modifications on the latching surface.
A hinged-mounted labeling panel is shown by Scholz in U.S. Pat. No. 4,725,921. This hinge-mounted labeling panel is to be used on plug-in modules and is fitted with a locking means. The device of Scholz is complicated to construct and requires a hinge arrangement and a structural modification of the subassembly which serves to mount the plug-in modules. The device of Scholz would be expensive and difficult to manufacture.
U.S. Pat. No. 5,161,994 to Sato et al is concerned with a board latching device to be used with a printed circuit board and a connector for connecting two printed circuit boards. The latching device of Sato et al requires openings in the printed circuit board with the metal latching means to be inserted into the openings therein and requires complicated fabrication in forming the latch device.
The metal latches shown by U.S. Pat. No. 5,154,627 to Lee are difficult to manufacture and require cutting and punching for their manufacture. Moreover, Lee requires two connectors for secure positioning of the boards.